1. Field of the Invention
This invention relates to an fan motor suitable for use for the cooling or the like of electronic instruments.
2. Description of the Prior Art
The recent tendency toward compactness in the design of various instruments has given rise to requirements for fan motors used therewith to be compact and inexpensive. Some products have been produced to meet those requirements, but none of them has yet sufficiently met the requirements.
For example, in a conventional fan motor shown in FIG. 1 of the accompanying drawings, a cylinder member 7 having a stator magnet 5 and a bearing 6 is mounted on a motor base 1 having a brush set 2 and a bearing 3; and an output rotary shaft 10 provided with a rotor coil 8 is supported by bearings 3 and 6 to thereby constitute a motor portion 15. A fan 12 is mounted on the rotary shaft 10, for example by pressing or adhesion. As shown in FIG. 2 of the accompanying drawings, a fan frame 13 is mounted on the base 1 of the motor portion 15 by means of screws 16 so that the fan 12 is contained therein. FIG. 3 is an exploded cross-sectional view thereof.
Such mounting of the motor requires the fan frame 13 to be thick and as a result, the length of the fan motor in the direction of the rotary shaft is increased. Also, a screw setting for mounting the motor is required, and this has led to a disadvantage that the number of steps required for assembly is increased and the motor becomes expensive.